1. Field of the Invention
The present invention relates generally to fluid ejection apparatus configured to eject droplets of fluid.
2. Description of Related Art
Known fluid recording apparatus, such as inkjet recording apparatus, eject ink droplets from nozzles to recording mediums, such as recording sheets, to form images, such as text images, on the recording mediums. An inkjet recording apparatus includes a fluid ejection head, e.g., an inkjet head, having nozzles, and an ink cartridge which stores ink therein and is connected to the inkjet head. When ink is consumed as ink droplets are ejected from the nozzles of the inkjet head, ink is supplied from the ink cartridge to the inkjet head.
Air may enter a passage, e.g., a fluid supply passage, which connects the inkjet head to the ink cartridge, e.g., when the cartridge is replaced. If air in the fluid supply passage flows into the inkjet head together with ink, ink may not be properly ejected from the nozzles. Ink is suctioned from the nozzles of the inkjet head using a suction pump in order to discharge air that is present in a portion of the fluid supply passage upstream of the inkjet head in an ink flow direction together with ink.
For example, in one inkjet recording apparatus, such as the inkjet recording apparatus described in Japanese Laid-Open Patent Publication No. 2005-199600, the inkjet recording apparatus includes a damper configured to absorb fluctuations in ink pressures. The damper is positioned at a portion of a fluid supply passage between an inkjet head and an ink cartridge, and is positioned upstream of the inkjet head. When a predetermined amount of air is accumulated in the damper, ink is suctioned from the nozzles using a suction pump to discharge air in the damper via the nozzles.
Nevertheless, the inkjet recording apparatus has to suction ink using a relatively large suction force to discharge air attached to a corner portion of the fluid supply passage upstream of the inkjet head from the nozzles of the inkjet head. Consequently, in the known inkjet recording apparatus, a significant amount of ink is discharged via the nozzles when air is discharged via the nozzles.